PMR and 13C NMR spectra of biologically active compounds.: XII.: Taraxasterol and its acetate from the aerial part of Onopordum acanthium

Crystalline taraxasterol and its acetate were isolated for the first time from Onopordum acanthium. Two-dimensional COSY, HSQC, and HMBC NMR experiments were carried out for complete assignment of signals in the PMR and C-13 NMR. Chemical shifts of stereochemically important methyl C atoms C-28 and C-29 were measured.